Dissertação
Atividade antimicrobiana do óleo essencial de camomila romana (Chamaemelum nobile)
Fecha
2019-03-11Autor
Barbosa, Marcelo Pires
Institución
Resumen
The increased prevalence of infections by multiresistant microorganisms has drawn
the attention of the scientific community to the need for new antimicrobial drugs. At the
same time, the perception of the inevitability of the development of resistance to these
agents led to a search for alternative methods to treat infections, such as the use of
agents without direct antimicrobial activity, but capable of preventing the expression of
virulence factors and potentializing the action of antimicrobials. Secondary plant
metabolites are rich in biologically active molecules and have become the subject of
intense research in this area. The present study aimed to evaluate such activity in the
essential oil of Chamaemelum nobile, popularly known as Roman chamomile. The
components of the oil were identified by GC-FID and GC-MS, the antimicrobial activity
was evaluated by broth microdilution and by antimicrobial synergism test with
amikacin. Inhibition of virulence factors were verified with tests of inhibition of biofilm
formation, inhibition of motility and interference in the quorum sensing system through
the inhibition test of violacein production. The analyzed oil presented α-pinene and β-
pinene as major components and a weak antimicrobial action against some strains of
Pseudomonas aeruginosa, Acinetobacter baumannii, Shigella sp. and Staphylococcus
sp. with MICs of 455 and 227 mg/mL. Oil concentrations of 14,2 and 7,1 mg/mL were
able to inhibit the production of violacein in Chromobacterium violaceum and
concentrations of 227 and 113 mg/mL inhibited the swarming and twitching types of
motility, but induced an increase in biofilm formation in P. aeruginosa PA01. The oil
showed strong modulatory activity of the amicacin activity in P. aeruginosa PA01
reducing the MIC for this antimicrobial by 128-fold.